Add HTML lang="en"

[skotfred]

Primarily an accessibility concern for screen reader software.

[julianfoad]

Hello. Thanks for offering a contribution to the Subversion project. Unfortunately, we looked at your patch and it seems that the changes themselves are mostly irrelevant, and those that add the "lang" attribute where it's not allowed by the DTD are actually wrong.

We encourage contributors to start at these pages:

https://subversion.apache.org/contributing.html
https://subversion.apache.org/reporting-issues.html

If you write to the mailing list, as described there, then we can help you come up with a correct fix for any problems you are seeing.

Thanks,

• Julian

[rhuijben]

The HTML 5 standard (As hosted on w3.org) explicitly allows the lang attribute on each element, including ''. See https://www.w3.org/TR/html52/dom.html#the-lang-and-xmllang-attributes

I'm not sure which DTD is refered to as 'the standard', but it is most likely targeting an outdated HTML version.